The present invention relates generally to signal triggers, and more specifically to real-time signal triggers based on autocorrelation characteristics.
Measurement instruments, such as spectrum analyzers and oscilloscopes, have the ability to acquire and analyze data in real-time. Examples of spectrum analyzers capable of making real-time measurements include Tektronix® WCA200, WCA300, RSA2200, and RSA3300 series spectrum analyzers, which are manufactured by Tektronix, Inc. of Beaverton, Oreg. These spectrum analyzers capture and analyze seamless blocks of data.
Measurement instruments have the capability to acquire, process, and display data faster than operators can meaningfully observe the data being presented. Triggers have been used in measurement instruments to start or stop the acquisition of data. These triggers have been based on time domain information about the input signal under analysis, and provided by an external source. Internal triggers capable of triggering on frequency spectral data have been used to display accumulated spectra following detection of a predefined spectra event. For example, a frequency mask trigger calculates the signal spectrum and triggers when the calculated spectrum violates a user-defined spectrum mask. A predefined block of data is stored containing information on what happened immediately before and immediately after the triggering event so that the operator can review the data, and perform post processing, as desired.
Triggers are desired to allow a measurement instrument to trigger on a variety of additional signal characteristics.